02-28-2021, 08:52 PM
(02-27-2021, 08:50 PM)GnR Wrote: Some of my photographs have a chromatic aboration problem where some colours are out of sync with others. The problem colour appears to be green but it might be more tricky than that. Assuming it is green..
I thought it might be possible to decompose the problem image into colour layers in GIMP, move the pixels of one layer over slightly, and recombine the layers. I don't know exactly which colour is out of sync or how much to move them so it is an experiment.
For the first attempt I decompiled the original image into RGB layers, which produces three greyscale layers.
Unfortunately the greys do not help me to see how much one colour is out of sync with the others, so I converted each layer to RGB and colourised them as the colour they are supposed to represent (red = hue 0, green = hue 120, blue = hue 240). I now have three distinct coloured layers that I can combine in various ways. I also created a solid white background layer.
However, I cannot find how to merge these layers to reproduce the original pre-decomposed image. Which transparency and layer modes should merge the red/green/blue layers to re-create the original image?
Tools to correct the chromatic aberrations are part of many demosaicing apps (they work much better when they can use the "raw" sensor data).